A former operations officer blamed her addiction to pain medications for embezzling more than $400,000 from a credit union’s vault and the accounts of elderly members over seven years.

Jade Carnahan, 35, of Scappoose, Ore., was sentenced Monday to 18 months in prison for bank larceny at the $4.7 million, 806-member Rivergate Federal Credit Union in Portland, according to the Portland office of the FBI. In April, Carnahan pleaded guilty to the felony charge.

U.S. District Judge Marco A. Hernandez in Portland also ordered Carnahan to serve three years of supervised release following her release from prison and to repay $408,062 in restitution, according to court records.

As the credit union’s operations officer, Carnahan had access to customer account information. Between July 2005 and July 2012, she embezzled more than $400,000 from the vault and from at least 18 member accounts, including elderly members, according to U.S. Attorney Amanda Marshall in Portland.

At sentencing, Carnahan blamed an addiction on pain medications in accepting responsibility for her crime, Marshall said.

“Crimes like this are especially offensive when perpetrated against seniors and have a lasting effect on the trust we place in our financial institutions,” Marshall said in a statement.

Drug abuse helps to drive crimes of opportunity, said Gregory Fowler, special agent in charge of the FBI in Oregon, in a statement.

“In this case, the defendant was in a position of trust to guard her bank’s funds and those of its customers,” Fowler said. “She broke that trust, using her access as a bank employee to feed a drug habit.”